// Copyright (C) Kumo inc. and its affiliates.
// Author: Jeff.li lijippy@163.com
// All rights reserved.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//

package utils

import (
	"bytes"
	"io"
	"mime/multipart"
	"net/http"
)

// PostFile upload file
func PostFile(reader io.Reader, url, fieldname, filename string) (*http.Response, error) {
	bodyBuf := &bytes.Buffer{}
	bodyWriter := multipart.NewWriter(bodyBuf)

	// this step is very important
	fileWriter, err := bodyWriter.CreateFormFile(fieldname, filename)
	if err != nil {
		return nil, err
	}

	_, err = io.Copy(fileWriter, reader)
	if err != nil {
		return nil, err
	}

	contentType := bodyWriter.FormDataContentType()
	bodyWriter.Close()

	resp, err := http.Post(url, contentType, bodyBuf)
	if err != nil {
		return nil, err
	}

	return resp, nil
}
